

NATURAL HISTORY. 



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annot persuade him that they are not the male clams. He knows they 

 These clam-worms are beautifully colored; they are of a general 

 greenish hue, but this is relieved by iridescent reds and 

 yellows. Along either side of the body are complicated 

 ' feet,' bearing bristles, while the mouth is provided with 

 a formidable pair of jaws, for the clam-worm is a savage, 

 predaceous animal, and his wanderings through the mud 

 are in search of his prey. 



Along with Nereis are other worms, one of which is 

 noticeable from the fact that when caught it throws out 

 a balloon-shaped proboscis, armed with four sharp hooks 

 which are strong enough to puncture the human finger. 

 This is a form known as Rhyncobolus. In Nejithys the 

 proboscis is much shorter. It is an interesting sight to 

 see these forms burrow. Placing one on the surface of 

 the sand, it crawls about for a few moments, and then 

 forces its proboscis beneath the surface, and then draws 

 the body together, the proboscis serving as an anchor. 

 Again the proboscis is forced forward, and again the 

 body is drawn forward, until in a very few moments the 

 whole worm is beneath the surface. 



In others of these wandering worms the body is cov- 

 ered with large scales. Small species of these are abun- 

 dant under stones below low-water mark, while from 

 deeper water the dredge occasionally brings up a form 

 four or five inches in length, in which the bristles are 

 very long and highly iridescent, so that the effect is 

 very beautiful. From the fact that these colors are not 

 lost even after prolonged immersion in alcohol, it would 

 seem that they are not produced by pigments, but are 

 rather of the nature of diffraction spectra. To these 

 larger scaly worms the term -sea-mouse' is applied, 

 although the reason therefor is not very evident. The 

 hairs are too long, the body too flat, and the colors too 

 bright to suggest the familiar rodent. The smaller scaly 

 worms have their beauty as well, though this is not evi- 

 dent in the day-time. In the dark, when their scales are 

 irritated, a beautiful green iridescence is seen. 

 There is one of these worms which is frequently taken in the skimming* 

 whirh. though small, has an interest for us. It is called Autolytas, 

 and Mr. Alexander Agassiz over twenty years ago discovered the peculiar 



Fig. 64.— Clam 

 Heter ■ a is). 



worm 



